Stellar Industries 91064 Main-Lift Cylinder Seal Kit for 7621 and 7630 V2 Cranes

If you’re unsure whether this part is compatible with your truck or equipment, please contact us to confirm fitment before purchasing.

The Stellar Industries 91064 Seal Kit is an OEM replacement sealing package for Boballee 71164 main-lift hydraulic cylinders with a 4.50-inch bore. This cylinder is used on compatible Stellar 7621 and 7630 V2 service cranes.

The kit replaces worn internal seals to help correct hydraulic leakage, pressure loss, cylinder drift, and reduced lifting performance. It allows the original cylinder to be rebuilt when its barrel, rod, and other structural components remain serviceable.

What This Part Is Used For

The Stellar 91064 kit restores sealing between the internal components of the crane’s main-lift cylinder. Proper sealing allows the cylinder to develop hydraulic force, raise the boom, and hold its position under load.

Common Reasons For Replacement

Hydraulic fluid leaks from the cylinder
Crane boom drifts downward
Main-lift cylinder will not hold pressure
Reduced boom-lifting performance
Cylinder movement is slow or inconsistent
Internal seals are worn or deteriorated
Contaminated hydraulic oil damaged the seals
Cylinder is being rebuilt during scheduled maintenance

Key Features

Stellar Industries part number 91064
OEM hydraulic cylinder seal kit
Designed for Boballee cylinder 71164
Services a 4.50-inch-bore main-lift cylinder
Compatible with select Stellar 7621 cranes
Compatible with select Stellar 7630 V2 cranes
Helps correct hydraulic leaks and cylinder drift
Supports complete main-lift cylinder rebuilding
Replacement seals supplied as one service kit